hi everybody
10 months ago I replaced the brakes with ebc redstuff and ebc slotted rotors.quiet an improvement.(jaguar x type 2006)
but the last weeks when braking down from 60mph, from 50mph till 20 mph a vibrating
roffling sound from the front. as soon as I stop braking the vibration is gone.
balanced the tires they are oke.inspected ,cleaned the brakes.still the same
problem.
any help,advice would be appreciated
thanks

 

wim, it sounds like to me that you have a rotor that has started to warp a little bit and that is leading to the vibration. You may also find that one of your pads is not wearing evenly and this is causing the one rotor to make a little bit of noise as you brake.

 

oke thermo
so I will remove both front rotors and will let those be checked for warping
in a machine shop.
will let you know if that was the problem.
thanks

 

well when we checked the rotors ,of both outside faces ,the surfaces were very uneven,very bumpy!!!
we decide to grind of both ,which was a little bit difficult because of the slots in the rotors.
installed them back androblem solved.

?what can cause this rotors become that bumpy?bad quality material?installation error?
I am really curious to know why this happened with nearly one year old rotors.

thanks

 

Usually an indication of poor quality, it depends on how old they are. The amount of heat your brakes, especially the front, generate is staggering. So you use the brakes they heat up, you don't they cool as you drive, the heat and cool process causes the metal to expand and contract which causes the warping. The rotors are vented to allow air between the sides to facilitate cooling better but crappy materials will warp faster and more unevenly.

 

wim, 2 big things can lead to rotor warpage. The obvious one is having water hit the rotors after a long/hard stop. This will quench one side of the rotors (causes the metal to contract) and the other side is still hot. This will cause the cool to want to twist towards the side of the car. Depending on the thickness of each side of the rotor and which side got more cooling, the rotor will flex towards the thicker side of the rotor or the side that got cooled more.

The other factor is the lugnut torquing. If you don't torque your lugnuts with an even amount of torque, this will induce stresses into the rotor which can lead to the rotor warping (kinda works the same way as the water). But, in this case, the stresses are there regardless of environmental conditions. This is where using a torque wrench or paying very special attention to how much you tighten the lugnuts can help prevent future problems.

But, as SWM said, the quality of the rotors can play into this too. Granted, this normally means that the rotors were either not heat treated properly (uneven heating) or the metal that they were using wasn't mixed all the way and you have different grades of metal on the various surfaces of your rotor.

 

Wim, I went with the same brake setup myself about a year and a half ago. I had the same exact issue for a while. Then it became intermittent, which I found very odd. First time using EBC brand. Stopping power was incredible but the noise and vibration was annoying. I just swapped out to Tire Racks setup of Brembo rotors and Akebono ceramic pads. When doing so, I discovered one of the Red Stuff pads had separated from the metal backing it was mounted to. They had about 35-40% life left on them to. I was shocked! Since you pulled and machined the rotors, I assume the pads were good? Btw, love the new setup on the brakes. Still embedding, as they call for 400-500 miles of "gentle" driving. Basically drive like a sane person. So far though, smooth, quiet, predictable, string braking power. Couldn't ask for better. I won't bother with slotted rotors again. Just my humble opinion.

 

Gotta update my car. She just passed 140,000 miles on her. A thing of beauty.

 

oke everybody thanks for the input and advices.

concerning the ebc redstuff pads,when we removed them for inspecting they were in good condition almost 90% life left and very smooth even surface.

when when we were machining the rotors we noticed some strange indent lines in the outside surfaces of both rotors,running from the inside to the outside of the rotors
which lead me to belief that those were caused by some sort of failure in the production process of these rotors.

this afternoon we will torquewrench all the wheelnuts with the same torque.
is there any factory advice for torqueing the wheelnuts?

thanks everybody

 

hi everyone one, i seriously have a serious issue on my hands at this time. my brakes were making a hissing sound when apply the pedal, so i was advised by mechanic to grind the surface of the front brake disc (i suppose that is what you call the rotors) which i have just done. Now my steering wheel vibrates so badly when the apply the brakes when am travelling at 60mph and stops when i get to about 45mph. i serious think i have made the worst decision of my life by allowing the disc to be grinded at a machine shop. will grinding the surface of the brake pads help solve this problem?. Any help will be appreciated

 

baffourg, if your steering wheel is only shaking when you apply the brakes, then you have a warped rotor. It sounds like to me that who ever "ground" (aka, trued up or turned) your rotors did it wrong. They somehow machined the rotors so one side of the rotor is thicker than the other (ie, the 12 o'clock position has more metal to it than the 6 o'clock position). Unfortunately, that can only be fixed by replacing the rotors. Granted, one thing that I will recommend you do before you go replacing rotors is to pull the rotors off of the car on the front end and take a wire brush to the hubs of the car (the area where the rotor makes contact to the suspension of the car) and then also wire brush the inside of the rotor where the hub touches the rotor. It is possible that they got a little bit of dirt or something on that surface and it is causing the rotor to not spin in a perfect circle. If you need me to be more specific, I will go into more detail.

 

will be grateful if u get into more details thermo

 

Using this picture as an example:

What you want to do is to remove the caliper and the support bracket for the caliper. Now, remove the rotor off of the car. If you see where I have painted the center of the rotor black, on the far side of that, there is a surface where the drivetrain comes in contact with the rotor. You want to clean this area. Both on the rotor and the drivetrain. You will want to use a wire brush and get that surface as smooth as possible. You may want to even consider using a little bit of sandpaper. If you use the sandpaper, you want to only use it enough to smooth things out. Once you start seeing bright silver metal, you have gone far enough. It doesn't need to be bright silver, just want it flat. Sanding will help show you the areas that are small high points (will see a small circle that has been sanded with a larger circle where no sanding has occurred). Do both of the front wheels and then see how things are.

I don't know if you have access to either a dial caliper or an outside micrometer, but you may want to also take a little bit of time and measure the thickness of the rotor in 4 or more spots (say the 12, 3, 6, and 9 o'clock positions). All the values should be within 0.001" of each other. As for checking trueness of the rotor, if you still have wobble after all this, then it pretty much confirms a bad rotor.

The only other thing that I would tell you to check is the ball joints and the upper strut mount for any play. But, I would think that if you had any play there, you would be getting a wobble regardless of applying the brakes. Hence why I am not focusing on that. But, if you are in the area, might as well check that.

 

Oh, one last thing. When you are installing the wheels, try to make sure that the lug nuts are all torqued to the same value. It is preferable to use a torque wrench (I torque my wheels to 100 ft-lbs), but as long as you can use the same force for each lugnut, that should be good too.

 

thanks man! i will use the weekend to try and fix this problem

 

ok, so eventually i had to settle for a used brake disc costing about $200. i wonder where the mechanic got that from but today i tried it and it works perfectly. currently am hearing this sound from the front suspension. its like an old spring bed, does that mean i need to change the top mount on the front suspension?

 

well,it lasted only two months and the front brakes started vibrating again when braking.
same problem as two months ago!apparently machining the rotors helped only temporarly,and the rotors warped again.
so I am going to replace this ebc rotors defenitly.

 

Rotor warp is very rare. Especially if you have new rotors. Shops and manufacturers will do anything to get your money. Brakes will leave residue on the rotors making them imperfect. Grab a cheap rotorary tool with a cleaning wheel and clean those puppies up. You can also smooth out unevenly worn brake pads instead of replacing them. Also the "less dust" pads are harder on rotors

 

Two things people do without realizing it are:#1 sit at a stop lite and hold the brake AFTER they have been using them for hard stops and #2 coming home after a hard run and wash (even a car wash) the car( hitting the rotors on the outside with cold water).

 

I say the #1reason for warping rotors is using an impact to put the wheels on. 100Lbs of torque is all thats needed, not 600! I always work on my own vehicles because shops just dont take the time to do things right. Also, i clean all my brake components, even the pads, with a table top wire wheel, every brake change. It helps so much